Well-drilling bit



June 10, 1952 P. A. MCMURDY ET Al. 2,599,854

WELL DRILLING BIT Filed DeC. l0, 1949 2 SHEETS--SHEET l /au/ A. fus/14ml,

0560? M @One/voo INVENTORS June 10, 1952 P. A. MOMURDY ET AL WELL DRILLING BIT Filed Dec. l0, 1949 2 SHEETS-SHEET 2 Pa u/ MS/Wurdy ATTORNEY Patented June 10, 1952 WELL-DRILLING BIT Paul A. McMui-dy and Oscar N. Donehoo, Houston, Tex.

Application December 10, 1949, Serial No. 132,326

' 7 Claims. (Cl. Z55-61) This invention relates to well drilling bits and it has particular reference to bits having interchangeable and replaceable blades.

The principal object of the invention is to provide a bit for the drilling of test holes, core drilling and the drilling of oil, gas and other wells, the peculiar adaptability of the bit for diversied drilling being made possible through a provision for interchanging the blades in a head for the selection of a blade design best suited for the Work it is to perform. This is accomplished without the necessity for changing the blade retaining head since the interrelated elements responsible for retaining the blades in operative relation to the head remain the same regardless of any variation in the specific design of blade employed.

Another object of the invention is to provide a drill head having a tapered and threaded pin for its attachment to a drill stem and further having circumferentially spaced, longitudinal grooves or cavities which extend preferably above the midsection of the unthreaded portion of the d rill head, each groove broadening at its upper terminus into a circular cavity which is adapted to receive a correspondingly shaped prominence on the shank of a bit which lies in the groove and is effective to prohibit downward displacement of the bit with respect to the head. Moreover, to prevent outward displacement of the bit shank from its groove, a retaining Asleeve having a smooth bore embraces the drill head and bit shanks and bears at its lower end on lateral arms formed on the shanks, thus to reinforce the latter against lateral pressure exerted on the bit.

Other objects will appear as the description proceeds, taken in connection with the accompanying drawing, wherein:

Figure 1 is an exploded View of a well drill bit constructed according to the invention.

Figure 2 is an elevational view of the bit assembled, partly in vertical section.

Figure 3 is a top plan View of the bit, and

Figure 4 is a transverse sectional View taken on line 4-4 of Figure 2.

This application is a continuation in part of applicants copending application, Serial Number 46,258, filed August 26, 1948, now abandoned,

Continuing with a more detailed description of the drawing, reference numeral I denotes generally the drill head having an axial bore II and a tapered and threaded pin I2 which is adapted to be screwed into the drill stem I3, a portion of which is shown in Figures 1 and 2. Spaced circumferentially of the head I0 is a series of longitudinal grooves I4 in the walls thereof, whose sides are parallel and which extend preferably past the midsection of the head, terminating in circular cavities I5. The lower end of the head is chamfered at a to accommodate the confronting edges of the series of blades h5 in the manner to be presently explained.

It is to be understood that the invention is not concerned with the particular shape or formation of the blades I6 since these elements will be designed to suit the peculiar work they are ex-l pected to accomplish. However, the invention doesV pertain to the manner in which the blades are attached to or installed in the drill head.

Each blade I6 is formed with a substantially straight walled shank II whose width equals that of the groove I 4 in'which it is adapted to lie, as shown in Figures 2 and 4. At the end of the shank is. formed a circular head or prominence I8 which is received by the correspondingly shaped cavity I5 at the .end of each slot or groove I4.

In applicants earlier application above identied, the drill head is shown to possess tapered slots or grooves receiving blade shanks of like formation but it is found that the blades I6 may be as securely held in the head in the manner herein described and more easily installed and removed than when the blade shanks are retained in tapered grooves, which latter are more difficult and costly to form.

The head I8 of the shanks prevent longitudinal displacement of the blades with respect to the head. To preclude lateral displacement, a sleeve I9, having a smooth bore is slid onto the drill head to frictionally embrace the same and the exterior surfaces of the blade shanks II, binding the sam-e in their respective grooves. An internal annular flange 20 is formed on the sleeve I9 at its top and bears against an annular shoulder 2I on the drill head at the base of the threaded pin I2. Y

Each of the shanks I4 has formed thereon oppositely disposed and laterally extending arms or wingsr 22 which are curved to conform to the body of the drill head against the chamfered portion a thereof. When all of the Vblade shanks are. in position in the grooves of the drill head and the sleeve I9 applied thereto, the lower end of the sleeve will bear against the collective arms of the shanks which form a compete circle around the drill head. Since the lower end of the drill stem bears against the upper end of the sleeve I9, the latter will not be displaceable longitudinally and =will thus present a bearing for the arms 22 of the shanks at its lower end to reinforce vthe 1 blades I 6 against lateral drag in drilling.

Manifestly, the construction as Shown and rde- I scribed is capable of some modifications and such modification as may be construed to fall within the scope and meaning of the appended claims is also considered to be within the Spirit and intent of the invention.

What is claimed is:

1. In a drill bit, a head( comprising a cylindrical body having a chamfered lower end, the side wall of said head having therein a threaded pin on its upper end and a series of longitudinal circumfer entially spaced grooves, each of said grooves i having parallel walls terminating in a circular cavity, a series of blades projecting below sa'i'd' head, each having a shankshap'edlto conform to and lying in a respective groove of said head and having a circular prominence on its end lying'in' theV circular'cavity of said groove, said Shanks each havingioppositely directed and curved wings disposed in the chamfer o'f said head'andv a sleeve having a smooth bore embracing said head-v and v engaging said Shanks and wings collectively to holdv said blades vagainst lateral displacement in relation tov said head.

2. Adrill bit including a circular head having a drill stem eng'a'gingpin on its upper end'and provided with a chamfered lower end, the side walls o'f said' head having therein a series of c'ir- .,engagi'n'glsaid shanks and said arms to prohibit lateral displacement of said blades with respect to: said 'head'.

5.' A drill bit, a circular Vhead having a cham`= ifere'd: lower end-and longitudinal grooves in its side wall, each groove being open at the lower kVend' of sa'id head and terminating in a circular cavity of equal depth but of greater width than SaidE groove, a series oi' 'blades projecting below said' head, a shankiintegral;witheachlbladefwhose' walls conform t'oi andi lie flush. against the walls of a groove of said head, a. circular prominence on the end of*` said. sh'ankia'nd lying in saidvcavity t'oh holdthe shank against longitudinal displace Y ment in said.. groove, a wing on each side of each cumferentially spaced,A straight walled grooves y opening at its periphery and lower end, said grooves each terminatingiat its opposite endl in a Y cavity o'filik'e depth but of Vgreater width than the' I groove, a series of blades ,projecting below said he'ad`,.a shank on each of said bladeshaving Sur-v 1 faces, shaped to' conform to the lwalls ofsaid grooves and adapted tov beinterchangeabl'y received therein whereby' theV outer surfacel'of' said shankl willv lie' flush with the' periphery of' said head, a head on each of said Shanksv conforming with and lying in the cavityrof a groove to pre'- clude downward displacement ofthe shank there-v onya curved armformed'on each side of` each'nf said Shanks, ,said curved arms collectively defining a, ring" lying in the chamfered' lower end of said'head,.and a sleeve embracing said head 1 and engaging the outerV surfaces of said blade Shanks' and arms to hold the same against" out'- ward' displacement' in said head.

A drill bit comprising acircular head having a ciiam'fered lower end and longitudinal grooves in its sidewall and spaced about its circumference open' at" the' lowerV end thereof, said grooves each having a' widened area at its'upper end, a series of. blades' extending below the lower end of said head alshan'k integral withv each blade Whose wa'llsi conform to thoseofsa'id grooves to be conformably received therein, a prominence von the end' or". each of said Shanks conformingin-shap'e to' and' received in theV widened area of said, groove, arms integral with each of said Shanks disposed' inthe chamferof said head and curved t'oc'onf'orrn to the curvature of the latter, and a sleeve'embracing Said head and engaging said sli'anksandV arms to hold the Shanks against endv wise and lateralv displacement with respect to said head;

4. A drill bit comprising a circular head hav-- ing a cnar'rreredl lower end and provided with of said Shanks and disposed in the chamfer of' said head` the outer surfacev of said. shankszand wingslbeingush withthe'periphery of said 'head and ay sleeve: snugly embracing said headand eri-Y gaging saidr Shanks and: wingszocollectively? toy hold said', blades against displacemehtl withv re spect tos'a'id. head.

6.` A drillA 'bit having a. circular head and a' chamfer'ed lower end and. provided with circum-y ferentially spaced, longitudinal grooves inrits side Wallyea'ch terminatingV in a widened. area Aat its upper' end, aseries ofY blades extendingfbelo'w' said head having' Shanks disposed' interchange ably in'- said-- grooves: each having. ar head. shaped to conform to a vvidenedarea and" disposed there;-Y in to hold'. the shank againstl longitudinalzdisplacement in the groove, a sleeve embracing said f he'adza'ndshank's to prohibit lateral'displacement oi'. said'. Shanks with respectt'o said head and op# po'sitelyy extending, arcuate `wings carried' byV each ofi said. Shanks disposed. in the: chamfer of said head and engageable-by the: lowen end 0f' said' sleeve to reinrorce ,said blades 'against lateral pressure in drilling.

7. The structure of claim 6, the blade rein-V forcing means consisting. of lateral wings oneach' bladefshank collectively forming a ringembracing the drill head adjacent Yits lower end.

PAUL A. MGMURDY. OSCAR No DONEHOO.

REFERENCES VCITED The following references' arev of record. inv the file O'f this patent:

UNITED' STATES PAIENTS'V Number Name Date 829,633 Decker ---A Aug.Y 28, 19.06 1,326,506 Humason ---"s-, Dec.` 30,-y 19,19 1,370,492 Smith.- etal. Mar.\1 1921- l,?-19;303-y Reed etal; ,Aug'. 18,193.1 2,498251 Creelk remar', i950 

